However, a fire official said it was not caused by a bomb. The official Bernama news agency said the blast could have been caused by a leaking gas tank.

"We scrambled 39 officers to the scene. We are investigating the cause of the explosion. It is one of the worst tragedies in the state in years. But it is not a bomb," he said.

"We recovered the bodies of three men. And we have helped in the evacuation of 24 people injured to the nearby public hospital," he added.

A video clip of the aftermath showed the facade of the store torn apart, with some people screaming for help.

"I was purchasing a pizza in front of the shop when suddenly a strong explosion occurred," George Sting, 39, said. "The workers in the shop immediately ran out," he said, adding that some were seriously injured.